This invention relates generally to imaging systems and more particularly to a method and apparatus for processing a fluoroscopic image.
In at least some known imaging systems, a radiation source projects a cone-shaped beam which passes through the object being imaged, such as a patient and impinges upon a rectangular array of radiation detectors.
In some known radiation detectors, such as those including thin film transistors (TFTs) and photodiodes, a xe2x80x9clagxe2x80x9d signal may occur. Lag is a dependence of an image signal due to the past exposure history. Some known medical applications require a transition from high radiation exposure to fluoroscopic mode, which uses low exposure. A lag signal from the high exposure may introduce artifacts into the fluoroscopic images in the form of ghost images of the high exposure image.
In one aspect of the invention a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array, acquiring a plurality of dark images to generate a baseline image, acquiring a plurality of lag images subsequent to the baseline image, determining a plurality of parameters of a power law using at least one lag image and at least one baseline image, and performing a logxe2x80x94log extrapolation of the power law including the determined parameters.
In another aspect, a medical imaging system for processing a fluoroscopic image that includes a detector array, at least one radiation source, and a computer coupled to the detector array and the radiation source is provided. The computer is configured instruct the medical imaging system to scan an object, acquire a plurality of dark images to generate a baseline image, acquire a plurality of lag images subsequent to the baseline image, determine a plurality of parameters of a power law using at least one lag image and at least one baseline image, and perform a logxe2x80x94log extrapolation of the power law including the determined parameters.
In yet another aspect, a computer readable medium encoded with a program executable by a computer for processing a fluoroscopic image is provided. The program is configured to instruct the computer to scan an object with an imaging system, acquire a plurality of dark images to generate a baseline image, acquire a plurality of lag images subsequent to the baseline image, determine a plurality of parameters of a power law using at least one lag image and the baseline image, and perform a logxe2x80x94log extrapolation of the power law including the determined parameters.
In yet a further aspect of the invention, a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array, acquiring a plurality of dark images to generate a baseline image, acquiring at least one first radiation image subsequent to the baseline image, acquiring a second dark image subsequent to the first radiation image, and acquiring a second radiation image subsequent to the second dark image. The method also includes generating a lag prediction image by subtracting the baseline image from the second dark image and subtracting the lag prediction image from at least one subsequent radiation image to generate at least one lag-corrected fluoroscopic image.
In still another further aspect of the invention, a method for processing a fluoroscopic image is provided. The method includes scanning an object with an imaging system including at least one radiation source and at least one detector array. The method further includes generating a baseline image, acquiring at least one radiation image subsequent to the dark image, processing a fluoroscopic image after acquiring a dark image every nth frame, and acquiring a dark image every nth frame, where n greater than 1.